Thermally responsive device



April 15, 1952 J. c. ALBRIGHT THERMALLY RESPONSIVE DEVICE 2 SHEETSSHEET1 Filed Oct. 21, 1948 mam-mnwm all!!! s v E N R 0 T T A IN V ENTOR.

H W e E v 5 W L O l W W Y O B d April 15, 1952 J. c. ALBRIGHT THERMALLYRESPONSIVE DEVICE Filed 001.. 21, 1948 2 SHEETSSHEET 2 INVENTOR.

A 7- TOR/YE Y5 I atented Apr. 15, 1952 THERMALLY RESPONSIVE DEVICE JohnC. Albright, Chicago, Ill., assignor of onehalf to William J. Adams,Chicago, Ill.

Application October 21,1948, Serial N 0. 55,7 97

This invention relates to a thermally responsive device.

The invention is concerned particularly with the type of thermostat inwhich the pressure of a substantial body of thermally expansiblematerial is concentrated on a plunger of relatively small crosssectional area to produce a relatively large axial response of theplunger commensurate with the relatively larger mass of the body whichis developing pressure. A device of this general type is disclosed inPatent 432,182 of July 15, 1890. The pressure developed by theexpansible body and communicated to the plunger may be used for anydesired purpose, as to open or close a switch'or valve, or to actuateany other part.

It is the purpose of the present invention to preclude leakage of theexpansible material outwardly along the bearing surface of the plungerwhile, at the same time, avoiding the destruction which usually followswhen a diaphragm is bent. The ordinary diaphragm subject to the pressureof a large mass of material on one face and en-,

gaged on its opposite face only by the plunger would obviously berequired, in effecting plunger movement, to become attenuated and cuppedto enter the plunger bore in propelling the plunger outwardly therein.According to the present invention, the expansible material is whollyconfined by a diaphragm in which motion'is effected by deformationrather than by flexing of the diaphragm. The material of the diaphragmis soft enough so that it actually flows and the form of the chamber issuch that it tapers curvilinearly at the point where the diaphragm isconfined therein, thus avoiding any sharp corners across which thediaphragm may be bent or cut.

More specifically, it is an object of the present invention to provide adeformable diaphragm which is one piece with a liner for the chamberwhich contains the thermally responsive material, the said liner beingextended over the mar gin of the chamber remote from the diaphragmportion of the liner and anchored to the chamber by a closure cap at theend thereof.

. A further important object of the present invention is the provisionof a construction in which the diaphragm or deformable portion of theliner is upwardly crowned, and the change in crosssectional area of thechamber in which the diaphragm is confined is effected gradually, theliner conforming to the interior shape of the chamber and preferably,though not necessarily, remaining without material change in wallthickness until it reaches the diaphragm or deformable plug portionwhich caps thetopof the chamber.

18 Claims. (01. 297-43) Other objects of the invention will be moreapparent from the following disclosure thereof:

In the drawings:

Fig. lis a vertical axial section through a device embodying theinvention.

Fig.2 is a view in transverse cross section taken on the line 22 of Fig.1.

Fig. 3 and Fig. 4 are fragmentary detail views showing in axial sectionslightly modified embodiments of the closure of the device of Fig. 1.

Fig. 5 is a side elevation showing a preferred embodiment of theinvention.

Fig. 6 is a View on an enlarged scale taken in section axially throughthe device of Fig. 5.

Fig. '7 is a view taken in section diagrammatically illustrating themanner in which the rubber insert shown in Fig. 6 is molded directly inthe chamber in which it is tooperate.

Fig. 8 is a view diagrammatically illustrating the molding into the formof a pellet of the thermostatically responsive material to be inserted.

Fig. 9 is a view showing the insertion of the pellet into the pre-moldedskirt.

The container 3 has the interior form of a bottle, comprising arelatively large chamber at 4 and a gradually tapering throat at 5leading to the cylinder portion 6 in which the power transmittingplunger 1 is reciprocable under the bias of spring 8. The sleeve shownat 9 is merely a conventional illustration of any suitable spring seat.

In the throat 5 and extending substantially to the beginning of thecylindrical portion 6 is a deformable diaphragm or plug H) which ismolded to provide integrally a liner or sleeve I ll extending downwardlyalong the inner wall of the throat portion 5 and the chamber portion 4of receptacle 3. The wall thickness of the skirt or liner II issubstantially uniform until it merges with the diaphragm or plug II], atwhich the inner surface is preferably upwardly concave as indicated at2, diverging sharply from the outer surface of the plug or diaphragmwhich is molded to fit and conform to the inner surface of thereceptacle where the tapered throat merges with the cylinder 6.

It will be observed that the portion of the rubber body In which isadjacent plunger 1 constitutes an elastically deformable plug which,when distorted, tends to resume its shape. That portion of the body ofrubber shown at II] which is nearest to the filling 20 hereinafterdescribed constitutes a diaphragm. Its operation is distinctly differentfrom that of a conventional diaphragm since there are no margins 3anchored at this end of the chamber where, due to repeated flexion andtension, they would tend either to tear or pull free. Instead, thediaphragm is anchored at the remote end of the chamber, as will now bedescribed.

At its end remote from the diaphragm or plug, the receptacle isoutwardly flanged at I3. The liner II has an outwardly flanged portionI4 and is preferably provided with a peripheral channel at l5 completelyenclosing the flange l3 of the receptacle. The channel is, however,non-essential, since the flange It forms an adequate seal when theclosure IB is applied and anchored by spinning its flange portion I!over the flange 13 of the receptacle, with or without the interveningchannel l5. The closure It must be substantially non-yielding inresponse to pressures developed within the receptacle, and accordingly,it is desirably reenforceol in some manner, as by convexing it upwardlyat its center at l8.

The space within the liner and the closure i8 is completely filled witha body 25 of any thermally expansible material, an example being thematerial disclosed in U. S. Patent No. 432,182 of July 15, 1890. Otherexamples include beeswax alone or in different compositions, and pastemixtures of resin or wax with crystalline materials. Among many suitableformulae are the following:

60 CsI-I4CL2' (paradichlorobenzene) 6.5% raw cocoanut oil 6.5% rawcastor oil 27% commercial beeswax 3 grams beta napthol .3 gram ester gumresin (No'rE.The figures given will make one pellet of thermallyresponsive material .375 inch in diameter and .437 inch long. Operatingwithin a skirt of comparable dimensions to move a piston having adiameter of .156 inch, this particular material will respond at 200 F.to produce a piston travel of .048 inch against a load of 150 pounds persquare inch.)

When the device is subjected to an increase in temperature, the rate ofexpansion of the filler 26 being greater than the rate of expansion ofthe receptacle 3, pressure is exerted on the receptacle and its liner inall directions.

The bottom closure [6 will not yield appreciably, but the pressurethereon will increase the binding engagement of its flange I! with theportion of liner channel which is confined against body flange [3. Theonly direction in which appreciable yielding can occur is in thedirection in which the deformable plug or diaphragm [0 can expand intothe cylinder 6, displacing the plunger 1 against the compression ofspring 8. Since the relatively small lineal movement in the relativelylarger cross section of chamber 4 is communicated into a cylinder of,very much smaller cross section, the lineal movement will be multipliedand is capable of operating a switch or other part in response to thechange in temperature. If the temperature is subsequently reduced, thematerial will shrink, and the parts will resume their original position,due not only to the compression of any spring used at 8, but due also tothe tension developed in the liner H and the plug it) during theexpansion. The expansion of material 2i} deforms the plug by forcing itinto a throat of progressively restricted cross section from which theplug tends to escape as it elastically resumes its original form.Tension is also distributed over substantially the entire liner ll,movement of the plug into the throat causing a slight attenuation of theliner which is resisted by its inherent elasticity, the liner beingdesirably made of natural or synthetic rubber, or a silicone or thelike.

The distribution of the stress throughout the entire liner precludes anypossibility of developing excessive strain at any one point. Leakage isalso precluded, since the liner itself provides the gasket between theclosure and the receptacle.

The fact that the seal is effected at the remote end of the chamber is agreat advantage in a small unit because the operating end thereof can beof much smaller. over-all diameter.

If desired, I may use a liner at 2| for the closure l6 as shown in Fig.3. .The material used at 2! may, if desired, be the same as that usedtomake up the liner II and plug 10. It takes the form of a disk, themargins 22 of which are included. within the flange H of closure [6 whensuch flange. is spun. around the flange 13 of the receptacle 3.Alternatively, the liner 23 may be of smaller diameter so that itsmargins, preferably skived as indicated at 24 in Fig. 4, will terminatebeneath the lower marign of receptacle 3, without being carried aboutthe flange l3 thereof. The liners 2| or 23 will ordinarily be used whenit is desirable to protect the closure l5 from the expansible material26 used within the device. However, the disks 2| and 23 may contributeto the effective seal of such material.

While I have referred to a plunger and to a cylinder portion of thereceptacle, it will be observed that the cylinder and plunger arenonessential to the operation of the device, since any part engaged bythe plug or diaphragm will be actuated thereby, the plunger being merelya preferred means of receiving and communicating motion.

While the forms of the invention heretofore disclosed are entirelysatisfactory, I prefer the embodiment now to be described, with thedetails of the method used in its manufacture.

The receptacle 30 provides an interior chamber 40 which is closelycomparable to that shown in Fig. 1, being provided with a throat 50tapering to the cylinder 60 in which the power transmitting piston orplunger 10 is operable. As above indicated, no spring is required andnone is here shown, the elasticity of the rubber plug I00 being reliedupon to restore the thermostatic pellet 2m] to its. original form as thedevice is cooled after operation.

The skirt portion H0 extending along the wall of chamber 40 from plugN10 is attached to the remote end of receptacle by means of cement 3|applied as hereinafter described. The closure I takes the form of a caphaving an outwardly projecting stud at l8! and an inwardly projectingboss at I82 against which the thermostatically responsive material 200seats. The channel I83 between the boss I82 and the flange I84compresses and conforms the reversely bent thermal portions III of theliner sleeve H0. Solder or brazing or the like is used at I85 to connectthe flange I84 of the closure cap I80 to the wall of the receptacle 30.a

amazes A preferred method of manufacture is as follows:

The receptacle 30 may be made in a screw machine or otherwise to theform indicated in Figs. 6, 7 and 9, the outer periphery of its open endbeing cut away to form an annular groove at 32. With the plunger 10closely fitting into the cylincler 60, the receptacle is placed in a die34 which has a cavity at 35 to receive it. The upper end of the die ispreferably flush with the open end of the receptacle.

The interior of chamber 40 of the receptacle is coated with any soap,the soap constituting a lubricant which prevents the rubber fromadhering thereto. Similar lubrication may be provided for the wall andthroat of the chamber 4 in the constructions previously described,although it is not as much needed in those devices. Adjacent its openend, however, the wall of the chamber 40 is coated with cement 3| whichpreferably extends about the open end and covers the surfaces of thegroove 32. Any rubber cement is usable, but it is preferred to employthe product known commercially as a nitrate dope primer, this being asynthetic latex.

Into the chamber 40 is now dropped a small ball of a rubber which issuitable. to use a synthetic rubber of 30 denier which is made by mixing80% by weight of hycar with 20% by weight of neoprene. For theparticular device shown, in which the interior of the sleeve H is tohave a diameter of .375, and a length of .437, the finished rubber plugand sleeve will include approximately one gram of rubber, but the ball36 initially inserted will desirably contain some excess, for example,one and threetenths grams.

The receptacle 30 is preferably preheated to 300 F. before beinginserted in the mold 34, which may also be heated by resistance element340. The ball of rubber is now subjected to a pressure of 800 pounds tothe square inch by means of a ram 31 as shown in Fig. 7, the shape ofwhich determines the interior shape of plug I00 and sleeve liner H0. Theram is shouldered at 30. The excess rubber escapes as flash as indicatedin dotted lines at H2. The rubber is held in the die under pressure ofabout 800 pounds until cured and vulcanized to the receptacle at theprimed open end thereof. After the cure is completed, the rubber willstand 500 F. without deterioration.

In order to make sure that the thermo-responsive filler shown at 200fills the lined chamber to capacity, it is preferred that the paste orother material to be used be preliminarily molded into a pellet as shownin Fig. 8. If desired, the thermally responsive material may be mixedwith an inert powder to give it body. A mold 20| is provided, the molddesirably having an ejection plunger 202 with projecting rod 203. Thethermally responsive material 200 is placed into the cavity of the moldand compressed by a ram 204 which desirably uses 8,000 pounds to thesquare inch. The resulting pellet 200 is form-sustaining and may, asshown in Fig. 9, be forced into the lining sleeve I [0. As shown in Fig.6, in the ultimate position of the pellet 200, the boss I 82 of theclosure cap I80 slightly enters and compresses the rubber at the openend of the receptacle. The device is again placed in a press andsubjected to any desired degree of high pressure suflicient not only toassure the elemination of all voids, but to overcome any tendency of thepellet 200 to expand during the soldering of It is preferred the flangeI84 to the external wall of the receptacle, which is now accomplished tocomplete the unit.

Such a device has the important advantage that its operating end is verysmall in diameter and may be used in closely confined quarters. It iscompletely sealed and has long life since, as above noted, there are nobending strains imposed on the diaphragm, its deformation being a matterof compression and its anchorage being effected through the elongatedlining sleeve H0, whereby such tension as is developed. is widelydistributed.

I claim:

1. In a pressure responsive device, a chamber having a side walldefining a pressure compartment and a pressure delivering throatproviding a progressively narrowing wall surface leading smoothly fromsaid side wall, together with an integral elastic diaphragm and plug insaid throat having a liner extending from said diaphragm along the wallof said chamber, said diaphragm and plug being deformable to fiow out-,Wardly and inwardly along said throat, means connected with said linerfor the anchorage thereof, and a body of material having a highercoefficient of thermal expansion than the chamber and confined thereinwithin said liner and diaphragm in all positions of deformation thereof.I

2. In a pressure responsive device, a chamber having a pressurecompartment of relatively large diameter and a cylinder compartment ofmaterially smaller diameter and a tapered throat providing a wallsurface which includes the side and end of the pressure compartment andthe side of the cylinder compartment, said surface gradually changingdirection between said compartments, together with a diaphragm spanningthe pressure compartment and having a liner extending along the wall ofsaid pressure compartment and provided with marginal anchorage theretoas a complete closure between said cornpartments, a deformable bodywithin said throat integral with said diaphragm and substantiallyfilling the space between the diaphragm and said throat and adapted tofiow toward the cylinder compartment in response to increase of relativepressure in the pressure compartment and a body of material having ahigher coefficient of thermal expansion than the chamber and confinedtherein within said liner and diaphragm and effecting the flow of saiddeformable body along said throat.

3. The device of claim 2 in which the anchorage is eifected by cement.

4. The device of claim 2 in which the anchorage is effected bymechanical pressure interlock, the said chamber having a closure cap andsaid sleeve having a flange confined between the closure cap and thechamber.

5. In a device of the character described, a bottle-shaped receptaclehaving a chamber for thermally expansible material and provided beyondsaid chamber with a gradually tapering throat and a cylindrical neck, aplunger reciprocable in said neck, an elastically deformable plug insaid throat and engaging said plunger, said plug having a dependingskirt extending from said plug along the interior surface of saidchamber and confined between said body and said receptacle, the saidreceptacle and skirt being flanged outwardly at a point remote from saidthroat and provided with a closure for which the outward flange of theskirt provides a gasket.

has achannel-shaped portion. completely enclosing the outward flange ofthe receptacleand.

substantially completely embraced. in a channelled flange of theclosure.

71. A device of the character described com.- prising: a receptaclehaving a chamber portion for thermally expansible material. opening toone end of the receptacle and a cylinder communicating'with. saidchamber portion and opening at. the one end thereof, a combination plugdiaphragm and lining. sleeve in the chamber portion, said sleeveextending. to the open end thereof, the receptacle at such end beingprovided with a groove about its perimeter at which the wall thicknessof the receptacle is reduced, the lining sleeve extending over the endof the receptacle and into said groove, a thermally expansible materialcompletely filling the lining sleeve, and a closure confining suchmaterial under pressure and in pressure engagement over the end of saidreceptacle with the lining sleeve portion turned thereover, and meansconnecting said closure with the receptacle whereby to maintain suchpressure engagement.

8. The device of claim '7 in which the interior of said receptacle islubricated to promote free movement of the sleeve, diaphragm and plugexcept adjacent the open end of the receptacle, the receptacle beingprovided interiorly adjacent its open end with cement connecting saidsleeve with the receptacle solely at such end.

9. The method of making a thermostat of the character described whichcomprises prefabricating an open-ended thermostat receptacle having anextension comprising a throat and cylinder, closing a portion of thecylinder against communication of the receptacle therewith, introducinga body of raw rubber into the receptacle, molding such rubber as in adie under heat and pressure directly in the receptacle in position foruse as a one-piece diaphragm and elastically attenuable liner for thereceptacle, said diaphragm constituting a partition between the cylinderand the said receptacle.

10. The method of making a thermostat of the character described whichcomprises prefabricating an open-ended receptacle having a throat andcylinder, introducing a body of raw rubber into the receptacle, moldingsuch rubber as in a die under heat and pressure directly in thereceptacle to constitute a one-piece diaphragm and liner for thereceptacle, said diaphragm separating the cylinder from the rest of saidreceptacle, vulcanizing the liner to the receptacle at a point remotefrom said cylinder while leaving it free of the receptacle elsewhere,pressing into the lined receptacle a preformed pellet of thermallyexpansible material and sealing the receptacle across the liner behindsaid pellet.

11. The combination with a receptacle comprising a chamber portion forthermally expansible material uniformaly converging at one end andlining the wall of said chamber portion and being free for attenuationin the movement of said plug, and the thermally expansible materialbeing confined within. the wall of said liner.

12.. The combination With. a. receptacle comprising a chamber portionfor a thermally ex-..

pansible material, a throat of reduced cross: section communicating withsaid chamber portion,

an elastic deformable plug in. said throat provided with a skirt-likelinerconforming to the wall of. said chamber portion and constitutingaiming therefor,. means anchoring; said liner to said receptacle at apoint axially remote from said throat, said liner being elastic and.free for attenuation in the movement of, said. plug, and a. closure. forsaid receptacle having-a1 lining. constituting; a closure for said.liner, thereby completely closing the: space within said liner.

13.. In a. device of. the character described, the combination. with areceptacle comprising a chamber for a thermally expansible material,.thewall. of. said chamber uniformly converging into a throat of decreasedcross" sectional. area, an elastic. deformable plug mounted within saidthroat, said plug having an elastic attenuable skirt-like. linerextending therefrom along the Wall of said chamber and forming a linerthere.- for, the body of. the thermally expansible. material beingcontained within saidv skirt and entirely filling the space therein,means at the opposite end. of said. receptacle. from. said pluganchoring said skirt: to said receptacle and allowing fre'e attenuationof. said skirt intermediate said anchoring means. and plug; and closuremeans closing the end. of said receptacle adjacent the region ofanchorageof said liner thereto.

14. The combination set. forth in claim 13; in.

tween the end of the chamber and closure and.

comprises a gasket.

15. In a receptacle, a bodyof thermally expansible material confinedtherein, a pressureresponsivemember contained within said receptacle andengaged at one side thereof with. said body and acted upon by said bodyupon expansion. thereof, an. extensible flexible liner extending fromthe margin of said pressure. responsive member along the wall of saidreceptacle and about said body of thermally expansible material, theinner end. of said" liner being closed. by said pressure-responsivemember and the outer end' of said liner being open and secured to theend of said receptacle remote from said pressureresponsive member, and aclosure member for the. open end of said liner and associated end ofsaid receptacle and reacted against by said body of thermally expansiblematerial, whereby pressure thereagainst by expansion of said bodyatten-tuates said sleeve and. effects the flowing of saidpressure-responsive member along said receptacle.

16;. In a. receptacle. a body of thermally expansible material confinedtherein, a pressureresponsive member contained within. said receptacleand engaged at. one side thereof w-ith said body and acted; upon by saidbody upon expansion thereof, an extensible flexible liner extending fromthe margin of said pressure-responsive member along. the. wall of saidreceptacle and about said. body of thermally expansible material, theinner end of said liner being closed by said pressure-responsive memberand the outer end of said liner being open and secured to the end ofsaid receptacle remote from said pressure-responsive member, a closuremember for the open end of saidliner and associated end of saidreceptacle and reacted against by said body of thermally expansiblematerial, whereby pressure thereagainst by expansion of said bodyattentuates said sleeve and effects the flowing of saidpressure-responsive member along said receptacle, and the connectionbetween the end of said sleeve and said receptacle being a cementedconnection.

17. A receptacle having a chamber portion for a thermally expansiblematerial and having a cylindrical portion for a plunger openingtherefrom, a diaphragm separating said cylindical portion from saidchamber and a skirt-like liner extending therefrom and lining the wallof said chamber, the said receptacle terminating in a flange having anexternal shoulder, and said liner extending over said flange, and aclosure member clamping against said flange and a portion of said linerextending thereabout and having a boss wedged against said liner andwithin said flange.

18. A receptacle comprising a chamber portion for a thermally expansiblematerial and having a cylindrical portion for a plunger openingtherefrom, a diaphragm separating said cylindrical portion from saidchamber and having a skirtlike liner extending therefrom and lining thewall of said chamber, the said receptacle terminating in a flange havingan external shoulder, the said liner extending over said flange, and aJOHN C. ALBRIGHT.

REFERENCES CITED The following references are of record in the .file ofthis patent:

UNITED STATES PATENTS 15 Number Name Date 1,399,780 MacDonald Dec. 13,1921 1,475,463 Weida Nov. 27, 1923 1,850,683 Merrill Mar. 22, 19322,259,846 Vernet Oct. 21, 1941 2 2,310,519 Eskin Feb. 9, 1943 2,368,181Vernet Jan. 30, 1945 2,456,615 Berglund Dec. 21, 1948 FOREIGN PATENTSNumber Country Date 345,050 France Sept. 28, 1904 531,280 Great BritainJan. 1, 1941 702,868 France Jan. 27, 1931

